1. Field of the Invention
This invention relates to an attitude reversing method and an attitude reversing device for reversing up and down the attitude of an assembly consisting of a plurality of objects in the course of an assembling operation.
2. Description of the Prior Art
Heretofore, in order to reverse the attitude of an assembly consisting of a plurality of objects in the course of an assembling operation, the assembly is first grasped by a first robot and is raised from a jig for assembling operation. Fingers of the first robot are then rotated by 90 degrees in a vertical plane to first set the attitude of the assembly in a sideways state. Subsequently, the assembly is grasped by a second robot, and the grasped state by the first robot is released. Fingers of the second robot are then rotated further by 90 degrees in a vertical plane. The assembly is thus transferred from the first robot to the second robot in a state in which the attitude of the assembly is reversed up and down, and is mounted onto the jig for the assembling operation by the second robot.
In the above-described attitude reversing procedure of the assembly, however, two robots are needed. In addition, the assembly must be transferred from the first robot to the second robot after the two robots have been brought close to each other. Hence, in addition to the need for two robots, the control of the two robots becomes complicated, and it takes time for an attitude reversing operation, causing increase in production cost.
When two objects are assembled by reversing a plurality of objects in one direction using a jig for reversing operation, the reversing direction of the jig becomes an issue. That is, as shown in FIG. 16, if a spur gear G.sub.1 and a shafted gear G.sub.2 are held in object housing units 1a and 1b formed on first and second surface 1A and 1B of a jig 1 for reversing operation, and the gears G.sub.1 and G.sub.2 are assembled by reversing the surfaces 1A and 1B in the right or left direction as shown in FIG. 16, respectively, the spur gear G.sub.1 becomes situated at an upper position in the case of reversing in the right direction, and the shafted gear G.sub.2 becomes situated at an upper position in the case of reversing the surface 1B in the left direction.
In recent assembling lines, a method has been used in which a plurality of robots assemble at least two objects by sequentially conveying them among the robots. In this case, when a third object (not shown) is assembled with the gears G.sub.1 and G.sub.2 assembled as shown in FIG. 16, the particular state between the state shown in FIG. 16(B) and the state shown in FIG. 16(C) is provided in the assembling process shown in FIG. 16(A) largely influences the increase or decrease of the assembling processes.